1. Field of the Invention
The invention relates to a promoter screening vector, to methods for the identification and isolation of Streptomyces promoters using the screening vector, and to the isolated promoters themselves, preferably the ps1 (SEQ ID No: 2) and p14 (SEQ ID NO: 1) promoters of the S. ghanaensis phage I19 which are described hereinafter.
2. Description of the Prior Art
Only relatively few strong promoters are hitherto available for homologous and heterologous gene expression in Streptomyces. The promoters hitherto described and employed for this purpose mainly derive from antibiotic-resistant genes and from other genes whose expression is regulated by other gene products.
In order to be able to utilize Streptomyces better as host organism for strong expression of any required gene there is a need for correspondingly strongly constitutive promoters as well as promoters of defined strength. Promoters of these types can be found, for example, in the DNA of lytic bateriophages.